Commutator clock



Nov. 22, 1960 H. R. CLARKE ETAL 2,951,500

COMMUTATOR CLOCK 3 Sheets-Sheet 1 Filed June 5, 1958 H hvHnmP INVENTORS HENRY R. CLARKE DONALD R. DAYKIN GEORGE T JUDSON mm mm NM BY SUGHRUE & ROTHWELL ATTORNEYS Nov. 22, 1960 H. R. CLARKE EIAL 2,951,500

COMMUTATOR CLOCK Filed June 5, 1958 3 Sheets-Sheet 2 UTILIZATION DEVICE POWER R SUPPLY 85 7 PROGRAME FIG; 5

Nov. 22, 1960 H. R. CLARKE ETAL COMMUTATOR CLOCK 3 Sheets-Sheet 5 Filed June 5, 1958 TIG 3 United States Patent COMMUTATOR CLOCK Henry R. Clarke and Donald R. Daykin, Vestal, and George T. Judson, Whitney Point, N.Y., assignors to International Business Machines Corporation, New York, N .Y., a corporation of New York Filed June 5, 1958, Ser. No. 740,077 11 Claims. (Cl. 200-38) This invention relates to improvements in commutator clocks and more particularly to a sequential circuit controlling device driven in a time-controlled manner and having selective time read-out control.

In automatic production recording systems it is necessary and desirable to provide a digital output of time or other information which may be recorded by any suitable device in a known manner. It is also desirable to program the occurrence of this time read-out. Accordingly, it is the principal object of this invention to provide a time driven device for providing a digital time read-out which may be selectively programed for operating a utilization device.

It is also an object of this invention to provide a commutator clock utilizing a plurality of modular units, each having printed circuits thereon which are sequentially connected by commutator brushes driven step-bystep by means of a ratchet and pawl arrangement in a time-controlled manner to provide an output wherein the connected circuit corresponds to the digital figure of time, and this circuit may at the same time be utilized to energize a selective printing device for recording this time figure. It is a further object of this invention to provide a time read-out control which may be programed to selectively disable the time read-out means. It is another object of this invention to prevent a time advance within the modular units during a read-out period. It is also an object of this invention to provide a visual time indication feature and readily accessible clock time setting means.

Although this invention is specially adapted for use in an automatic production recording system, it is not limited thereto but could find utility in any system wherein it is desired to provide a programed output of information in digital form corresponding to sequentially connected circuits. This invention is especially adapted to provide a time readout and this is the illustrated preferred embodiment, however the invention is not limited to a timed readout but has capabilities to initiate any automatic production recording system digital readout.

With the above and other objects in view, the invention contemplates providing a clock-driving motor which drives a plurality of modular units, each employing a ratchet feed arrangement. Each of the modular units includes a printed circuit construction in combination with commutator brushes to provide the digital time read-out. An electric switch is provided in series with the digital read-out circuits for each modular unit, and a rotating program disc has means carried thereon for selectively preventing actuation of this time read-out control switch. After the least significant digit modular unit advances to its radix, the unit actuates the next succeeding unit through a cam actuated ratchet and pawl feed arrangement. When this unit reaches its radix it again actuates the next succeeding unit and so on to the most significant digit. Interposer means are provided to prevent all of the modular units from advancing to the next digit while a read-out or impending.

The device is flexible to the extent that the modular units may be interchanged to provide a read-out in either conventional time or in continental time and may further be adapted to provide a read-out in hours and minutes or in hours and thousandths of hours.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose by way of example, the principle of the invention and the best mode which has been contemplated of applying that principle.

In the drawings:

Fig. 1 is a side elevational clock of this invention with the Fig. 2 is an exploded view units shown in Fig. 1;

Fig. 3 is an end elevational view taken along section 3-3 of Fig. l with certain of the motor supports removed for clarity;

Fig. 4 is a partial and elevational view similar to Fig. 3 illustrating another embodiment of the time advance delay means which are operable during read-out; and

Fig. 5 is a simplified circuit diagram of one modular unit and its associated time read-out control switch in combination with a utilization device.

Referring to the drawings, Fig. 1 illustrates the commutator clock of the invention assembled to provide time read-out in hours and minutes. The device is supported on a base 10 having an upright front support wall 12 to which is secured a synchronous clock motor 14 by means of a motor support bracket 16 and suitable screw and nut means 18.

A plurality of modular units 20a, 20b, and 20c are removably and interchangeably secured to the base by means of suitable angle supports 21. Referring to Fig. 2, each modular unit comprises an upright printed circuit board 22 of insulating material having a suitable printed circuit pattern 23 thereon. In the illustrated embodiment this pattern 23 includes a common lead extending around two-thirds of the circumference of the commutator path and ten sequential leads in the other third of the path. Electrical connector brackets 25, Fig. l, are provided to connect the leads 23 on the printed circuit board to other electrical leads and to a utilization device such as a typewriter print-out (not shown). The board 22 has an opening 24 therein for the purpose of supporting a bushing 26 which in turn journals the commutator brush, ratchet, and program disc assembly 27. This assembly includes a flanged shaft 28 having projecting locating pins 29. A commutator brush disc 30 of electrically conductive material is assembled against the face of the flange of shaft 28, and this brush disc has, in the preferred embodiment, three resilient brushes 32 mounted thereon. The brush disc 30 is assembled within a commutator drum 34 having a projecting flange 36 upon which numerals may be inscribed. In the preferred embodiment the numerals 0 through 9 may be inscribed on the outer surface of the flange 36 of modular unit 20a three times around its circumference. A ratchet wheel 38 having ratchet teeth 39 and a program disc 40 having a plurality of equi-spaced slots 42 in the periphery thereof are assembled along the axis of the assembly cycle is in progress view of the commutator cover removed; of one of the modular shaft 28 and are suitably located by the projecting pins' 29. The ratchet wheel 38 and the program disc 40 are.

gram clips 44 for a purpose which will be described. Each modular unit except the one for the most significant digit or hours 20c, shown in Fig. 1, contains a three-lobe drive cam 46 which is secured to the shaft 28 at one end thereofon the opposite side of the printed circuit board 22 from the commutator assembly 27.

All the modular units, except the one for the least significant digit 20:: shown at the left in Fig-1, are driven a from the preceding modular unit by means of the threelobe cam 46 cooperating with a drive mechanism 47. Thisdrive .mechanismincludes a cam follower 48 having a surface 49 adapted to contact the periphery of the three-lobe cam 46 on the adjacent modular unit. The cam follower 48 is freely pivoted about stub shaft 50, Fig. 2; and is biased to its cam-engaging position bya pawl driving spring 51 which is secured to an adjustable support 52. The cam follower '48 also has a projecting tab 54 which extends toward the commutator assembly. A feed pawl drive arm 56 is also mounted for free pivotal movement about stub shaft 50 and this arm carries the feed pawl 58 which is pivoted thereon at point 59 and biased to its ratchet-engaging position by a spring 60. The feed pawl drive arm 56 is provided with an ex tension 62 which extends outwardly from the unit and which may be used as a clock setting lever when the unitis provided with a cover. The cam follower 48 and the feed pawl drive arm 56 are connected and biased in contacting relation by means of spring 64 such that the tab 54 on the bottom of the cam follower 48 contacts the bottom of the feed pawl drive arm 56. When/the high point of the surface of three-lobe cam 46 of one modular unit engages surface 49 of the cam follower arm 48 of another adjacent unit, feed pawl. driver arm 56 and feed pawl 58 will pivot'downwardly together about mounting stud 50. The cam follower arm 48"and the feed pawl drive arm 56 are separately pivoted but biased to move together so that when the cam follower surface 49 is riding on one of the high points of the lobe of the three-lobe cam 46 the clock-setting lever extension 62 may still be actuated by applying downwardly acting force to the outer end thereof to move drive arm 56 independently of follower arm 40 and thereby set the numeral on flange 36 to the correct time indication. Spring.64 will then return the feed pawl 53 when the force .on the clock-setting lever'extension is removed.

Aneccentric feed pawl stop stud 66 is positioned to limit the upward movement of the feed pawl and this stud.is-att'a'ched by suitable nut 67 to the printed circuit board..22. The eccentricity of stud 66 provides the means for adjustably positioning the stopping surface of the stud, thereby varying the limit of upward movement of the feed pawl 58. A detent pawl 68 is alsofreely'pivotedabout mounting stud 50 and is biased to pawl-engaging position by spring 69 secured to mounting pin 70.

The. drive for-modular unit 20a shown at the:left. in: Fig.- l is..through a main cam 72 which is secured to a shaft 73.driven in time-controlled manner by'the motor- 14. The main cam 72 has three separate cam surfaces thereon. These cam surfaces are the drive cam surface 74, the. sensing arm cam surface 75, and the interposer knock-off cam surface 76. Referring to Fig. 3, the drive arm cam surface 74 has one sharp drop-off and this cam is contacted by a drive arm cam follower 78 which is' rigidlysecured to pivotally mounted shaft 80. The cam follower surface 81 of the cam follower arm 78 is biased against the drive cam 74 by a suitable spring 82 secured to .an adjustable support 83. The feed pawl drive arm 56 .Iof. the first stage modular unit 20a, shown at the leftlof :Fig. 1, is also rigidly secured to pivotable shaft. 80Iand hence will follow the movements of the drive arm cam follower 78 therebyaccomplishing a feed of one ratchet .tooth every time the cam follower surface 81. drops ofilthe drop off in cam 74.

Time read-out .control is accomplished by energizing. a suitable snap-actingswitch 84, Figs 3, whichmaybe 1 connected in series with the common lead on the printed circuit board 22. Switch 84 is suitably supported by a bracket 86 and this switch is in the illustrated embodiment a conventional snap-acting two-pole switch. The switch blade is normally biased to open the circuit between this blade and pole contact 87. The normally closed pole of the switch may be optionally used to control an auxiliary circuit not shown herein and not a part of thisinvention. The switch 84 is adapted to be actuated by an insulated actuator 88'which is attached to a sensing arm 90 thereby closing the circuit between switch blade 85 and switch contact 87, Fig. 5. The sensing arm 90 is rigidly secured to a pivotably mounted shaft 92. Also rigidly attached to pivotable shaft 02 at the end thereof adjacent cam 72 is a sensing arm cam follower 94-. The cam-engaging surface 95 of sensing arm cam follower 94 is biased against sensing arm cam 75 by a suitable spring 96, Fig. 3. The sensing arm 90 is mounted such that the lower end 93 thereof will engage a clip 44 which may be positioned in a slot 42 of program disc 40 in the path of arm 90 when it swings inwardly by actuation of cam 75 and follower 94. If there is aprogram clip 44 in the path of the end 98 of sensing arm 90, the arm will abut this clip and be prevented from further pivoting upwardly thus preventing actuator 88 from closing switch 8 1-. there will be no time read-out since the connection the commutator brushes. 32 are making with the printed circuit leads 23 will' be open circuited, Fig. 5. Therefore selective positioning of the clips 44 in the slots 42 of the movable disc 40 maybe used to provide a programed time read-out control.

Fig. 5 is a simplified circuit diagram of the printed circuit board '22 of one modular unit and the switch 84 con-- nectedto a utilization device, a power supply, and a sepa rate programmer. Switch 84 serves to make and break the supply of power to the programmer which in turn controls the make and break of power to the commoned conductor of the printed circuit pattern.

An interposerassembly is arranged to delay the time advance and prevent'the advancing of the commutator brushes in the modular units during a read-out of the clock. If a time advance were to occur during a readout, it could easily give an erroneous reading. For instance, assuming'the clock is to be read-out at 11:59. Reading out of these digits would start with the most significant digit to operate a printing device printing from left to right, such as a typewriter. After reading out the first two digits (11: should a time advance occur,

the clock would advance to 12:00. As the read-out continues through the next two digits the printed document would show a read-out of 11:00, because the time advance'occurred between the second and third digits and the first two had already been read-out and printed. The read-out would thus be incorrect. The interposer assembly which prevents the above-described situation comprises an interposer arm 100 freely pivotable about a mounting stud 102 and biased by a spring 104 to a position wherein a cam-engaging surface 106 may be engaged by the interposer knock-oif cam 76. An interposer latch 108 is mounted for free pivotal movement about mounting stud 110 and is biased by spring 112 such that a.v

latching ear 114 will attempt to engage an extreme end 116 of interposer arm 100." A time advance delay mag: net 118 is mounted on front support wall 12 in a manner such that it may attract the interposer latch 108 which acts as its armature against the bias of spring 112. The drive arm cam follower 78 has a projecting pin 120 which projects to a point where it may be engaged in a neck 122 of interposer arm 100. The time advance delay magnet 118 may be pulsed or energized for apredetermined period of time prior to read-out, to allow sufficient time for the necessary'mechanical motions to accomplish the necessary results. Energization of the mag-j net -118 picks up the-interposer latch 108 releasing the" In this condition interposer arm 100 allowing spring 104 to move it inwardly to engage the pin 120 of the cam follower arm 78 within neck 122 when the cam follower arm 78 is moved downward, as viewed in Fig. 3, by the high point of cam 74. As the interposer arm 100 engages the drive cam follower arm 78 it prevents this arm from dropping the high point of drive cam 74 and thus prevents a time advance. The interposer knock-off cam 76 having its high point positioned approximately 180 from the high point of the time advance cam 74 knocks the interposer arm 100 clear of the cam follower arm 78 after a time during which any read-out could be safely completed. As time advance cam follower arm 78 is freed from interposer arm 100, spring 82 causes cam follower surface 81 to move against time advance cam 74 thereby pivoting shaft 80 and causing a one-step advance of the feed pawl 58 of modular unit 20a. The delay of the cam follower arm 76 from dropping off cam 74 would not cause the clock to become slow because this amount of delay would be gained at the next drop-off of the time advance cam 74 which would occur 180 after the interposer arm 100 is knocked out of the way of the time advance cam follower arm 78.

Fig. 4 illustrates a modification of the interposer assembly wherein the assembly is directly controlled by a solenoid rather than through the means of separate mechanical latches. In Fig. 4, the interposer arm 130 is freely pivoted on stud 132 to the position shown in full lines in Fig. 4 wherein the neck 134 of the interposer arm is engaging the pin 120 of the time advance cam follower arm 78. The interposer arm 130 in this modification is actuated by a solenoid 138 having a movable plunger 140 with a pin 142 which engages a hole 144 near the end of the interposer arm 130. A spring 131 serves to normally bias the interposer arm 130 to the non-engaging position shown in phantom lines. When a time read-out is to occur, the solenoid 138 is pulsed to energize the armature and thereby move interposer arm 130 to the full line position when it will engage and prevent the time advance cam follower arm 78 from falling off the high point of cam 74. At any desired time after a time read-out the armature of the solenoid 138 may be de-energized to allow the spring 131 to move the interposer arm 130 and unlatch the time advance drive arm 78. This arrangement of a directly actuated interposer latch provides a more flexible control of the latching arrangement and eliminates the need for the interposer latch and interposer knock-01f cam, although the knock-off cam 76 could be and is used in the Fig. 4 embodiment as a fail safe device to eliminate even the remotest possibility that the interposer arm 130 could continuously prevent the advance of the clock. In this embodiment cam 76 acts to release the arm 78 approximately 180 after engagement by the interposer as described above.

The operation of the device will now be described. When the clock motor 14 is energized, the motor will drive the shaft 73 in a time-controlled manner thereby rotating main cam 72. Rotation of cam 72 will cause rotation of the time advance cam portion 74 thereby causing time advance cam follower arm 78 to pivot as it drops off the high point of cam 74. Pivoting of follower arm 78 causes pivotal movement of shaft 80 and thereby pivotal movement of the feed pawl drive arm 56 of the modulator unit 20a. This causes the feed pawl 58 of the first stage modular unit 20a to advance the corresponding ratchet wheel 38 one notch corresponding to one digit. The commutator brushes 32 will then make an electrical circuit connection with the leads 23 on a printed circuit board 22 corresponding to the digit to which the commutator assembly has moved. After the first stage commutator assembly has moved to digit 9, the three-lobe cam 46 has moved to the position where its high point will cause cam follower 49 of the next stage modular unit to fall off at the next step of the feed movement. The movement of cam follower 40 of modular unit 20b also causes a pivotal movement of the feed pawl drive arm 56 of this modular unit and thereby drives its commutator assembly through one ratchet tooth space in a manner similar to that described for modular unit 20a of Fig. 1. In a similar manner, the three-lobe cam of the second stage modular unit 20b will cause a drive for the third stage modular unit 200 after the radix of modular unit 20b has been reached. If there are no program clips 44 in the slots 42 of the program disc 40 there may be a time read-out every revolution of the main cam 72 and therefore every revolution of the sensing cam 75. Sensing cam 75 causes sensing cam follower 94 to rock shaft 92 which in turn moves sensing arm and causes actuator 88 to actuate switch 84 if there are no program clips 44 in the path of the end 98 of sensing arm 90. If there are clips in the path, the actuator 88 does not accomplish the circuit closing function, and no read-out occurs. To prevent a time advance during readout when the successive stages are being read-out from the most significant digit while the time input is to the least significant digit, the interposer actuator magnet or solenoid, as shown in either Figs. 3 or 4, is energized to allow the interposer arm 100 or to engage the time advance cam follower arm 78 and prevent its falling oif from the high point of time advance cam 74 and thereby prevent advance of the time during read-out as explained above. The interposer knock-off cam 76 may then be utilized to restore the interposer arm 100 to its previous position after a sufiicient time for read-out has passed or the solenoid 138 may be de-energized to restore interposer arm 130 of Fig. 4. Visual time indication may be obtained by observing the numerals on flange 36 through a window which may be provided in the cover. If the clock indication of time is incorrect it may be set by means of levers 62 which will project through a clock enclosing cover.

The flexibility features of this invention are important. The individual stages or modular units 20 may be of different number and different type depending on the type of clock desired. If it is desired to provide a clock calibrated hours and minutes, the second or middle modular unit as viewed in Fig. 1 is graduated from 0 through 5 three times around its periphery and the ratchet teeth and circuit leads are formed accordingly. If it is desired to graduate the clock in hours and thousandths of hours, there is provided one more modular unit 20 and each of the first three units as viewed from the left are graduated from 0 to 9 three times around their periphery. In either case a three-lobe cam may be used for transfer from one stage to another when the graduations are inscribed three times around the periphery of each stage. Also more than one brush per modular unit may be employed to provide more than one digit per printer circuit. For example, in a continental hours module two brushes are used to provide two digit representing signals.

Various other modifications considered to be within the spirit of this invention will be apparent in view of the foregoing. For example, the sensing arm actuator for the time read-out control switch may be programed through only one revolution of the program disc. If, however, means were provided for selectively connecting the sensing arms to the rockable shaft 92 this programing could be carried out during more than one revolution of the program disc for the corresponding modular unit.

While there have been shown and described and pointed out fundamental novel features of the invention as applied to the preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

7 What is claimed-is: 1. An apparatus for providing a digital output, said apparatus comprising; at least one modular unit having a plurality of electrical leads carried thereby, said leads representing digital information, a commutator brush rotatably driven for sequentially connecting the electrical leads on said modular unit to provide a digital time readout corresponding to the connected circuit leads, a rotatable program member rotatably driven with said commutator brush, said program member carrying selectively positioned clips, a switch in circuit with the commutator connected leads, a switch actuator intermittently driven and movable in the path of said selectively positioned clips :for selectively preventing and permittingenergization of the commutator connected circuit, and interposer means for preventing an advance of the commutator brush while a read-out periodis-in progress or impending.

2.-A commutator clock comprising; a modular unit having a printed circuit on the surface thereof, a rotatable commutator brush adapted to sequentially energize selected leads in said printed circuit, means for driving said commutator brush in a stepwise manner, and a rotatable program member also driven in a stepwise manner, said program member carrying selectively positioned clips, a switch in circuit with the commutator connected leads'of the printed circuit, a switch actuator intermittently driven and movable in the path of said selectively positioned clips for selectively preventing and permitting energizetion of the connected circuit means.-

3. A modular unit sub-assembly for use inacor'nmutator clock, said sub-assembly comprising; an insulating board carrying a plurality of electrical circuit leads thereon in printed circuit form, a rotatable commutator brush adapted to selectively and sequentially connect one of said circuit leads with a common lead, a rotatable com mutator drum having visible indicia on its periphery representative of the connected lead, said drum attached to said brush, a ratchet rigidily connected with the movable commutator brush, a pivoted pawl arrangement for driving said ratchet one step at a time and thereby connecting the next sequential electrical lead, and a program disc attached to said brush and having means for selectively carrying at least one program clip'in the periphery thereof.

4. A device as defined in claim 3 wherein said pivoted pawl is provided with an eccentric stop and-a spring driver; 7 r

5. A'device as defined in claim 4 wherein said pivoted pawl is actuated by a three-lobe-cam and a cam follower and said commutator brush is rigidly connected to said three lobe cam at the same end thereof as the program disc.

6. A selectively sequential circuit controlling apparatus for providing a digital read-out corresponding to time,

said apparatus comprising; a time-advance cam driven in a time controlled manner, a plurality of modular units, each of said modular units'comprising an insulated circuit board having a plurality of electrical leads in the form of a printed circuit thereon, a rotatable commutator brush for sequentially connecting said leads, a program disc adapted to hold at least one program clip, and aratchet, cam follower means driven by said timeadvance cam for actuating-a pawl to feed the ratchet of the first modular unit and therefore drive said commutator brush to connect another electric circuit, a time read-out control switch in serieswith the connected electric circuit for selectively connecting this'circuit to a source of energy, means actuating said time control read-out switch from said main cam, said means being movable'in the path' of said program clip carried by said program disc, and interposer means for preventing the advance of said feed pawl during read-out.

7. A device as defined in claim 6 further comprising a cam rigidly connected with the rotatable commutator brush of each modular unit, a cam follower on each modular unit cooperating with the cam on the preceding modular unit, and said cam follower actuating a ratchet and pawl feed arrangement for the succeeding modular units.

8. A device as defined in claim 6 wher'ein'said 'interposer means comprises a movable interposer arm adapted to selectively cooperate with and hold said cam follower means driven by said time advance cam during a time read-out period and thereby prevent advance of the commutator brush of each of said modular units during readout;

9. A device as defined in claim 8 further comprising a latch assemblyfor latching the interposer arm in inoperative position and operable to allow the interposer arm to'move to its cam follower means holding position, and a cam connected to the main cam for moving the interposer arm out of holding position and move it to inoperative position where it is latched by the latch assembly.

10. A device as defined in claim 8 wherein said interposer arm is selectively actuated to'hold said cam follower means to prevent a time'advance and release said means to allow a time advance by a solenoid and bias means acting on said interposer arm.

11. A selective sequential circuit controlling device for providing a digital read-out corresponding to time, said device comprising; at least one modular unit having a printed circuit defining a plurality of electrical leads on the surface thereof, a rotatable commutator brush adapted to sequentially connect selected leads in said printed circuit, means including a cam and cam follower for driving said commutator brush in a stepwise manner, a rotatable program member also driven in a stepwise manner, said program member carrying selectively positioned clips, a switch in circuit with the commutator connected leads of the printed circuit, a switch actuator intermittently driven and movable in the path of said selectively positioned clips for selectively preventing and permitting energization of the commutator connected circuit, and means for disabling the drive means for preventing an advance of the commutator brushes while a read-out period is in progress or impending by disabling said cam follower.

Sohm Sept. 23, 1919 Olah et al. Jan. 12, 1954 

